Pain is generally defined as an unpleasant sensory and emotional experience, associated with actual or potential tissue damage (Wileman L, Advances in pain management, Scrip Report, 2000).
Acute pain is a physiological response to an adverse chemical, thermal or mechanical stimulus that may be associated with surgery, trauma or acute illness. These conditions include, but are not limited to, post-operative pain, sports medicine injuries, carpal tunnel syndrome, burns, musculoskeletal sprains and strains, musculotendinous strain, cervicobrachial pain syndromes, dyspepsia, gastric ulcer, duodenal ulcer, kidney stone pain, gallbladder pain, gallstone pain, dysmenorrhea, endometriosis, obstetric pain, rheumatological pain, headache or dental pain.
Chronic pain is a pain condition beyond the normal cause of an injury or illness and may be a consequence of inflammation or serious, progressive, painful disease stages. Various types of chronic pain include, but are not limited to, headache, migraine, trigeminal neuralgia, temporomandibular joint syndrome, fibromyalgia syndrome, osteoarthritis, rheumatoid arthritis, bone pain due to osteoarthritis, osteoporosis, bone metastases or unknown reasons, gout, fibrositis, myofascial pain, thoracic outlet syndromes, upper back pain or lower back pain (wherein the back pain results from systematic, regional, or primary spine disease (radiculopathy)), pelvic pain, cardiac chest pain, non-cardiac chest pain, spinal cord injury-associated pain, central post-stroke pain, cancer pain, AIDS pain, sickle cell pain or geriatric pain.
Neuropathic pain is defined as pain caused by aberrant somatosensory processing in the peripheral or central nervous system and includes painful diabetic peripheral neuropathy, post-herpetic neuralgia, trigeminal neuralgia, post-stroke pain, multiple sclerosis-associated pain, neuropathies-associated pain such as in idiopathic or post-traumatic neuropathy and mononeuritis, HIV-associated neuropathic pain, cancer-associated neuropathic pain, carpal tunnel-associated neuropathic pain, spinal cord injury-associated pain, complex regional pain syndrome, fibromyalgia-associated neuropathic pain, lumbar and cervical pain, reflex sympathic dystrophy, phantom limb syndrome and other chronic and debilitating condition-associated pain syndromes.
There remains a need to provide an effective treatment for pain.